Merge master.kernel.org:/pub/scm/linux/kernel/git/dtor/input

[powerpc.git] / arch / powerpc / kernel / kprobes.c

diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index 511af54..cfab485 100644 (file)
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -35,7 +35,6 @@
 #include <asm/kdebug.h>
 #include <asm/sstep.h>
 
-static DECLARE_MUTEX(kprobe_mutex);
 DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
 DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
 
@@ -54,19 +53,17 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
 
        /* insn must be on a special executable page on ppc64 */
        if (!ret) {
-               down(&kprobe_mutex);
                p->ainsn.insn = get_insn_slot();
-               up(&kprobe_mutex);
                if (!p->ainsn.insn)
                        ret = -ENOMEM;
        }
-       return ret;
-}
 
-void __kprobes arch_copy_kprobe(struct kprobe *p)
-{
-       memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
-       p->opcode = *p->addr;
+       if (!ret) {
+               memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
+               p->opcode = *p->addr;
+       }
+
+       return ret;
 }
 
 void __kprobes arch_arm_kprobe(struct kprobe *p)
@@ -177,11 +174,23 @@ static inline int kprobe_handler(struct pt_regs *regs)
                        save_previous_kprobe(kcb);
                        set_current_kprobe(p, regs, kcb);
                        kcb->kprobe_saved_msr = regs->msr;
-                       p->nmissed++;
+                       kprobes_inc_nmissed_count(p);
                        prepare_singlestep(p, regs);
                        kcb->kprobe_status = KPROBE_REENTER;
                        return 1;
                } else {
+                       if (*addr != BREAKPOINT_INSTRUCTION) {
+                               /* If trap variant, then it belongs not to us */
+                               kprobe_opcode_t cur_insn = *addr;
+                               if (is_trap(cur_insn))
+                                       goto no_kprobe;
+                               /* The breakpoint instruction was removed by
+                                * another cpu right after we hit, no further
+                                * handling of this interrupt is appropriate
+                                */
+                               ret = 1;
+                               goto no_kprobe;
+                       }
                        p = __get_cpu_var(current_kprobe);
                        if (p->break_handler && p->break_handler(p, regs)) {
                                goto ss_probe;